Pyrazolone coupler for color photography



Patented Mar. 7, 1944 UNITED STATES PATENT oFmc PYRAZOLONE cournna Fort coma rno'rocasrnr- Jersey No Drawing.

Application September 4,1942,

Serial No. 457,319

8 Claims.

This invention relates to photographic colorforming compounds and particularly to coupler compounds which are derivatives of pyrazolones for color forming processes of color photography.

This application is a continuation-in-part of our application Serial No. 419,172, filed November 14, 1941, now Patent 2,311,081, granted February 16, 1943.

The formation of colored photographic images by coupling the development product-of aromatic amino developing agents with color forming or coupling compounds is well known. In these processes the subtractive process of color formation is ordinarily used and the image dyes are intended to be of the complementary primary colors cyan or blue-green, magenta, and yellow. The couplers which produce the cyan dyes are usually phenols or naphthols, those producing the magenta dyes are ordinarily p azolones or cyano 'acetyl compounds, and those producin the yellow dyes are ordinarily compounds con-' taining a methylene group having two carbonyl groups attached to it. The dyes produced by coupling areazomethines, indamines or indo- .phenols depending upon the composition of the coupler and of the developer.-

In our copending application Serial No. 457,276, filed of even date herewith, we have shown that couplers believed to be acylamino derivatives of pyrazolone have valuable proper-'- ties for purposes of-color photography. We have now found that pyrazolone derivatives which we believe to be aryl-substituted amino derivatives of pyrazolone also possess valuable properties as couplers for the production of magenta dyes in color forming methods of color photography. Our novel couplers have the following general formula: 4

in which R and R are aryl groups.

The following examples} illustrate compounds of this general formula which are suitable for use according to our invention:

fl- H:

. 1-phenyl-3anilino-5-pyrozolono I N;c- NnOooH= I I l-phenyl-a-p-anisyl-amino-5-pyrazolone (ll-CH2 O QL I l-phenyl-li-p-su liamylphenyI-amincS-pyrazolone The aminopyrazolones used as starting materials in this reaction may be prepared in various ways. One suitable method which is described is recrystallized from 300 cc. of 95% ethanol toyield 12 g. of white feathery needles; M. P. 218-220.

0111' couplers are designed forv use in processes in which the coupler is incorporated in the developing solution such as those described in Mannes and Godowsky U, S. Patent 2,113,329, granted April 5, 1938, Or Marines. Godowsky and Wilder U. S. Patent 2,252,718, granted August 19, 1941. Certain of the couplers of our invention may be incorporated in sensitive emulsion layers for use in processes such as those described in Fischer U. S. Patent 1,055,155, granted March 4. 1913, Mannes and Godowsky U. S. Patents 2,304,939 and 2,304,940, granted December 15, 1942, and Jelley and Vittum U. S. Patent 2,322,027, granted June 15, 1943.

The following examples illustrate developing solutions containing the couplers used according to our invention:

Example 1 A. 2-amino-5-diethylaminotoluene h yd r ochloride -grams 2 Sodium sulfite (anhydrous) do 2 Sodium carbonate (anhydrous) do 20 Potassium bromide do 1' Water to liter 1 B. 1-phenyl-3-anilino-5-pvrazolone grams 2 Sodium hydroxide 10% solution) cc 10 B is added to A Example 2 A. Dimethyl-p-phenylenediamine sulfate.

grams 3 Sodium sulflte (anhydrous) do 5 Sodium carbonate (anhydrous) do 20 Potassium bromide do--- 2 Water to liter 1 B. l-phenyl-3-p sulmamyl phenylamino-5- pyrazolone grams 3 Isopropyl alcohol cc.. 100

B is added to A The foregoing example refer to the addition of the coupler compound to the developing solution itself. The coupler may also be added to the emulsion layer provided that suitable means are used to prevent its diffusion in the case of multilayer coatings. Special dispersing agents may be used for incorporating the coupler compound in the emulsion and in certain cases the coupler may be absorbed or adsorbed to the sensitive salt or may be combined with the sensitive salt as a chemical combination. Certain of the coupler compounds described in the present application such as No. 4 are in themselves non-difiusing and may be incorporated in the photographic layer without the use of additional agents to prevent diffusion. This coupler may also be incorporated in an emulsion layer according to the methods of Mannes and Godowsky U. S. Patent 2,304,940, and Jelley and Vittum U. S. Patent 2,322,027, referred to above.

In the development of exposed photographic silver halide emulsion layers, using the couplers of our invention, any color forming developer containing a primary amino group may be used. These include developers having two primary amino groups as well as those having one 01' the amino groups substituted or having substituents in the ring such as alkyl phenylenediamines and alkyl toluylene diamines. These compounds are usually used in the salt form such as the hydrochloride or the sulfate which are more stable than the amines themselves. The suitable com pounds are diethyl-p-phenylenediamine hydrochloride, monomethyl-p-phenylenediamine hydrochloride, dimethyl-p-phenylenediamine hydrochloride and 2-amino5-diethylaminotoluene hydrochloride. The p-aminophenols and their substitution products may also be used where the amino group is unsubstituted. All of these developers have an unsubstituted amino group which enables the oxidation products of the developer to couple with the color forming compounds to form a dye image. Our development process may be employed for the production of colored photographic images in layers 01' gelatin or other water-permeable, colloidal carriers, such as collodion, organic esters of cellulose, or synthetic resins. The carrier may be supported bya transparent medium such as glass, a cellulose ester or a non-transparent refleeting medium such as paper or an opaque cellulose ester. .The emulsion may be coated as a single layer on the support or as superposed layers on one or both sides or the support. The superposed layers may be differentially sensitized and the dyes formed therein by coupling may be bleached by an oxidizing agent such as chromic acid to colorless soluble compounds. struction of the dye in this way does not destroy the silver image and a silver image may be developed, bleached and developed to color images in superposed layers as described, for example, in Mannes and Godowsky U. S. Patent No. 2,113,329.

The examples and compounds set forth in the present specification are illustrative only and it is to be understood that our invention is to be taken as limited only by thev scope of the appended claims.

We claim:

1. A color-forming photographic developer comprising a primary aromatic amino developing agent and a coupler compound having the Probable formula:

in which R and R are aryl groups.

2. A color forming photographic developer comprising a primary aromatic amino developins agent and a coupler compound having the probable formula:

The dein which R and R are aryl groups of the benzen series.

3. A color forming photographic developer comprising a primary aromatic amino developing agent and a coupler compound having the probable formula:

4. A color forming photographic developer comprising a primary aromatic amino developing agent and a coupler compound having the probable formula:

5. The method of producing a magenta colored photographic image in a gelatino silver halide emulsion layer which comprises exposing the layer and developing it with a primary aromatic amino developing agent in the presence of a couplercompound having the probable formula:

in which R and R are aryl groups.

6. The method of producing a magneta colored photographic image in a gelatino silver halide emulsion layer which comprises exposing the layer and developing it with a primary aromatic amino developing agent in the presence of a coupler compound having the probable formula:

7. A photographic emulsion for forming colored images comprising a water-permeable colloidal carrier containing a sensitive silver halide and a coupler compound having the probable formula:

in whichR and R are aryl radicals.

8. A photographic emulsion for forming colored images comprising a gelatino silver halide emulsion containing a coupler compound having the probable formula:

HENRY D. PORTER. ARNOLD WEISSBERGER. 

